<div id="top-menu">
    <div id="top-menu1">
        <ul id="menu">
            <li><a href="/">Trang chủ</a></li>
            <li><a href="#">Hệ thống</a>
                <ul>
                    <li><a href="/monitor">Monitoring</a></li>
                </ul>
            </li>
            <li <?php echo ($_action=='admin/detail') ? 'class="active"' : '' ?>><a href="/admin/detail">Cá nhân</a></li>
        </ul>
    </div>
    <div class="clearfloat"></div>
</div>